1. Field of the Invention
The present invention concerns a device for installation of a gradient coil unit into a magnetic resonance apparatus.
2. Description of the Prior Art
For the installation of heavier components of a medical apparatus, an auxiliary device is frequently required that assists the technician. The mass of a gradient coil unit of a magnetic resonance apparatus is generally more than 100 kilograms, such that installation thereof into the magnetic resonance apparatus is not possible without auxiliary means. In magnetic resonance apparatuses, the gradient coil unit is supported (mounted) within a basic field magnet. A gap thus exists between the basic field magnet and the gradient coil unit. This gap is only a few millimeters, while the diameter of the receptacle (retainer) for the gradient coil unit is several hundreds of millimeters. It is therefore necessary to exactly position the gradient coil unit. In particular the magnetic center of the gradient coil unit must be positioned at the magnetic center of the basic field magnet with a tolerance of approximately 1 mm. The axes of symmetry of basic field magnet and gradient coil unit must additionally be aligned counter to one another with a tolerance of 0.1°. Once the alignment of the gradient coil unit is achieved exactly, lining parts are installed into the gap with a positive fit and the gradient coil unit is fixed in this manner.
To install the gradient coil unit it is known to accommodate the gradient coil unit by means of a carrier device and to insert it into the basic field magnet. The alignment ensues by means of shims (wedges) arranged between the gradient coil unit and the basic field magnets. A rotation ensues utilizing gravity by means of shims that are not centrally mounted, so a tilting of the gradient coil unit is achieved. The described procedure is exceedingly time-consuming and laborious for the implementing technician.
A transport cart or carriage for a gradient coil unit is known from EP 0 552 542 A1. The transport cart is fashioned such that different types of gradient coil units can be transported therewith. Spacers can be introduced between the basic field magnet and the gradient coil unit to align the gradient coil unit within the basic field magnet.
A method and a device for horizontal mounting of liners in high-pressure tank construction is described in East German PS 119 297. A tube bundle is thereby supported on transport segments. To align the tube bundle within a high pressure jacket, the transport segments are supported on three-point supports that can be vertically adjusted at three points of the floor or base by means of leveling elements.